First off, the animal, preferring thick vegetation, inhabits island swamps and thickets off the coast of West Australia—mainly on Rottnest Island (map) and Bald Island—as well as eucalyptus forests and riverbanks on the mainland.

These social plant-eaters hang out in clans, munch on swamp peppermint and other greens, store fat in their tails for lean times, dig tunnels through vegetation for napping and hiding, and hop likekangaroos—a close relative (along with wallabies).

Not surprisingly, quokkas have adapted nicely to the human invasion: They're bold enough to bound through streets and as skilled as raccoons in pilfering trash for goodies. They also don't seem to mind posing for Facebook-worthy pictures. (Related: "The Science of Selfies: A Five-City Comparison.")

Marsupial expert Yegor Malaschichev, a zoologist at St. Petersburg State University in Russia, sees no harm in snapping photos with quokkas—but he warns not to touch them, which is illegal. (That also means no hugging the animals, no matter how huggable they seem.)

Even more important, Malaschichev said, is not to feed the quokkas, especially "what we think they may like to eat."

An example: The animals will happily (and adorably) nibble away at a visitor's vegemite sandwich, but the bread "sticks between their teeth,which can later cause an infection called lumpy jaw," says Malaschichev, who has received funding from National Geographic.

Feeding quokkas is a bad idea, echoes conservation biologist Sue Miller of the University of Western Australia, who has worked with the "soft like a cat" animals for several years.

"People tend to feed them fries, bread, or fruit, and the animals become trusting of humans, which can cause problems. Animals that live farther away from [tourist activity] would probably hop away when approached."

And, she says, there is always the risk of being bitten. These are wild animals, after all.

Indeed, quokkas bite dozens of people at Rottnest each year, usually children. Injuries aren't serious, and most likely occur accidentally as the animals snatch snacks from small fingers.

Quokka Threats

Oddly, the quokka can thank criminals for its abundance on Rottnest: Late 1830s legislation designated the island an Aboriginal penal colony, which kept most everyone else away (thus leaving habitat intact).

Mainland quokkas, once widespread in West Australia, weren't so fortunate.

Habitat alteration and destruction since human colonization, plus hunting and poisoning of these "vermin," has done a number on their numbers and pushed most survivors to relative safety on small islands like Rottnest.

Since their introduction to Australia in the 1930s, foxes have developed a taste for quokkas. Fox and domestic cat predation, land clearing, and the risk of fire or disease spreading through an isolated population are the main threats to the animals today, Miller says. (Also see "Primitive and Peculiar Mammal May Be Hiding Out in Australia.")

Other Australian animals have suffered, too: Of modern-day mammal extinctions, mammals Down Under account for about a third, including 16 marsupial species and subspecies presumed gone for good.

Quokkas have fared better than many, but they still need help, and conservationists are on the job.

Recovery efforts—whose goal is to at least maintain the animals' current numbers and distribution—have focused mainly on controlling predators and better managing the quokkas' forest and island habitat.

On quokka-heavy Rottnest, that also means ensuring camera-wielding tourists aren't overstepping their bounds.

If all goes well, these photogenic critters will be smiling for years to come.